Abstract

The thermal transport in partially trenched silicon nitride membranes has been studied in the temperature range from 0.3 to 0.6 K, with the transition edge sensor (TES), the sole source of membrane heating. The test configuration consisted of Mo/Au TESs lithographically defined on silicon nitride membranes thick and in size. Trenches with variable depth were incorporated between the TES and the silicon frame in order to manage the thermal transport. It was shown that sharp features in the membrane surface, such as trenches, significantly impede the modes of phonon transport. A nonlinear dependence of thermal resistance on trench depth was observed. Partial perforation of silicon nitride membranes to control thermal transport could be useful in fabricating mechanically robust detector devices.

Received 23 January 2009Accepted 10 April 2009Published online 06 May 2009

Acknowledgments:

The authors greatly acknowledge NIST Quantum Devices Group at Boulder for providing SQUID array for TES readout. We thank Matthew E. Kenyon from JPL for useful discussions of thermal transport and device microfabrication aspects. The work at Argonne National Laboratory, including the use of the facilities at the Center for Nanoscale Materials (CNM), was supported by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a US Department of Energy Office of Science Laboratory, is operated under Contract No. DE-AC02-06CH11357. Work at the University of Chicago is supported by the National Science Foundation through Grant ANT-0638937 and the NSF Physics Frontier Center Grant PHY-0114422 to the Kavli Institute of Cosmological Physics at the University of Chicago. It also receives generous support from the Kavli Foundation and the Gordon and Betty Moore Foundation.